TY  - JOUR
AB  - We introduce the concept of a cloud-antichain, which is a natural generalization of antichains in partially ordered sets, and solve some seemingly basic extrenal problems for them. Following the discovery of our identity (in[1]) we found the ‘missing term’, which converts Bollobás' inequality into an identity. It immediately yields the uniqueness in the Sperner Theorem for unrelated chains of subsets, which are an example of a cloud-antichain.
DA  - 1990
DO  - 10.1016/0012-365X(90)90381-Q
LA  - eng
IS  - 3
M2  - 225
PY  - 1990
SN  - 0012-365X
SP  - 225-245
T2  - Discrete Mathematics
TI  - On cloud-antichains and related configurations
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-17751207
Y2  - 2024-11-21T23:18:39
ER  -